800
FXUS63 KFSD 310816
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
316 AM CDT THU JUL 31 2025
KEY MESSAGES
- PATCHY AREAS OF FOG WILL BE POSSIBLE THIS MORNING. WITH
VISIBILITIES OF 5 MILES OR LESS POSSIBLE THROUGH MID-MORNING,
BE PREPARED FOR RAPID CHANGES IN VISIBILITY OVER SHORT
DISTANCES.
- WILDFIRE SMOKE WILL CONTINUE TO PROGRESS THROUGH THE REGION
INTO THE WEEKEND. WHILE MOST OF IT WILL STAY ALOFT, SOME
LIMITED SURFACE IMPACTS WILL BE POSSIBLE.
- A FEW SCATTERED SHOWERS WITH AN OCCASIONAL RUMBLE OF THUNDER
WILL BE POSSIBLE THIS AFTERNOON MAINLY WEST OF THE JAMES RIVER
VALLEY. HOWEVER, SEVERE WEATHER IS NOT EXPECTED.
- MORE CONCENTRATED PRECIPITATION CHANCES (40%-60%) RETURN
BETWEEN SATURDAY AND SUNDAY. HOWEVER, UNCERTAINTY REMAINS ON
THE COVERAGE/ SEVERE RISK.
DISCUSSION
ISSUED AT 314 AM CDT THU JUL 31 2025
TODAY & TONIGHT: A SLIGHTLY WARMER DAY AHEAD! TAKING A LOOK ACROSS
THE AREA, CLEARER CONDITIONS ARE STARTING TO RETURN NORTH OF I-90 AS
A MID TO LOW LEVEL CLOUD DECK CONTINUE TO PUSH SOUTHWARDS THIS
MORNING. HOWEVER, WE'RE ALSO STARTING TO SEE A MIX OF PATCH FOG AND
WILDFIRE SMOKE MOVE INTO THE AREA AS WELL LEADING TO OCCASIONAL
VISIBILITIES OF 5 MILES OR LESS AT TIMES. WHILE THE FOG WILL LIKELY
PERSIST THROUGH THE MID-MORNING BEFORE DISSIPATE, EXPECT THE AREAS
OF WILDFIRE SMOKE TO CONTINUE ALOFT FOR MOST OF THE DAY WITH LIMITED
SURFACE IMPACTS. BESIDES THAT, MOSTLY QUIET CONDITIONS ARE EXPECTED
FOR AT LEAST THE FIRST HALF OF THE DAY AS SOUTHEASTERLY SURFACE
WINDS HELP INCREASE OUR HIGHS TO THE MID 70S TO LOWER 80S FOR THE
DAY.
LOOKING AT THE SECOND HALF OF THE DAY, A SURFACE HIGH WILL SLIDE
DOWN FROM SASKATCHEWAN/MANITOBA KEEPING MOST AREAS EAST OF THE JAMES
RIVER VALLEY RAIN-FREE FOR THE DAY. AS FOR AREAS WEST OF THE
PREVIOUSLY MENTIONED AREA, SCATTERED SHOWERS WILL LIKELY DEVELOP IN
THE LATE AFTERNOON TO EARLY EVENING AS A MID-LEVEL WAVE SLIDES
ACROSS THE MISSOURI RIVER VALLEY. WITH ABOUT 300-600 J/KG OF
INSTABILITY AND 30-40 KTS OF SHEAR, CAN'T RULE OUT AN OCCASIONAL
RUMBLE OF THUNDER WITH THE STRONGEST ACTIVITY. HOWEVER, SEVERE
WEATHER IS NOT EXPECTED. SINCE THIS ACTIVITY WILL BE RUNNING INTO A
MORE STABLE AIRMASS EAST OF THE JAMES, NOT EXPECTING THIS ACTIVITY
TO PERSIST PAST THE EARLY EVENING BEFORE DISSIPATING. SHIFTING GEARS
HERE, WE'LL LIKELY HAVE TO WATCH FOR ADDITIONAL AREAS OF FOG
OVERNIGHT MAINLY EAST OF I-29 AS LIGHTER SURFACE WINDS AND HIGHER
DEW POINTS COULD LEAD TO SOME LOCALLY DENSE AREAS. LASTLY, EXPECT
ANOTHER COOL NIGHT WITH TEMPERATURES FALLING INTO THE UPPER 50S TO
LOW 60S
THE WEEKEND: LOOKING INTO THE WEEKEND, WE'LL LIKELY HAVE TO DEAL
WITH SOME ADDITIONAL SHOWERS AND THUNDERSTORMS WEST OF I-29 TO START
THE DAY ON FRIDAY AS ANOTHER MID-LEVEL WAVE TRACKS THROUGH THE AREA.
HOWEVER, AS THIS DEVELOPING ACTIVITY GETS FURTHER AWAY FROM THE
BETTER INSTABILITY GRADIENT OVER WESTERN SD AND RUNS INTO A MORE
STABLE AIRMASS; SHOULD SEE THIS ACTIVITY GRADUALLY WEAKEN WITH
EASTWARD EXTENT. NONETHELESS, WE COULD SEE THIS PATTERN RINSE AND
REPEAT DURING THE AFTERNOON TO EVENING HOURS ON FRIDAY AS THE 850-
925 MB JET STRENGTHENS THOUGH SEVERE WEATHER IS NOT EXPECTED.
SHIFTING GEARS HERE, WE'LL LIKELY CONTINUE TO HAVE AREAS OF SMOKE
THROUGH AT LEAST THE WEEKEND AS CANADIAN WILDFIRE ROTATES AROUND THE
PREVIOUSLY MENTIONED SURFACE HIGH INTO OUR AREA. WHILE MOST OF THE
SMOKE WILL LIKELY STAY ALOFT, CAN'T RULE OUR AN OCCASIONAL "BURNING
SMELL" AT THE SURFACE ALONG WITH SLIGHT REDUCTION TO VISIBILITY IN
OUR HIGHER ELEVATION AREAS.
MORE CONCRETE PRECIPITATION CHANCES (40%-60%) LIKELY RETURN BETWEEN
SATURDAY AND SUNDAY AS THE SURFACE HIGH GRADUALLY PUSHES EASTWARDS
AND IS REPLACED BY A SURFACE WARM FRONT. SCATTERED SHOWERS AND
THUNDERSTORMS WILL LIKELY DEVELOP AS THIS BOUNDARY INTERACTS WITH AN
APPROACHING MID-LEVEL WAVE. WHILE THE SEVERE THREAT IS LARGELY
UNCERTAIN AT THIS POINT, WE'LL LIKELY HAVE TO WATCH THE SUNDAY
MORNING TIME FRAME FOR SOME ISOLATED POTENTIAL GIVEN THE INSTABILITY
AND BUOYANCY WITH APPROACHING WAVES. LASTLY, AS WARM AIR ADVECTION
(WAA) INCREASE AS THE WARM FRONT PUSHES INTO CENTRAL SD; WE'LL
LIKELY SEE TEMPERATURES TREND TOWARDS NORMAL HEADING INTO NEXT WEEK
WITH HIGH LIKELY IN THE 70S TO LOW 80S HEADING INTO NEXT WEEK.
NEXT WEEK: HEADING INTO THE NEW WEEK, AN ACTIVE PATTERN WILL
CONTINUE ALOFT WITH MULTIPLE WAVES PASSING THROUGH BETWEEN MONDAY
AND WEDNESDAY. THE STRONGEST OF WHICH WILL LIKELY PASS THROUGH ON
WEDNESDAY. WITH LONG RANGE GUIDANCE DIVERGING IN TERMS OF THE
PLACEMENT OF SYNOPTIC SCALE FEATURES AND SUBSEQUENT BOUNDARIES, THE
COVERAGE AND SEVERE RISKS REMAIN LARGELY UNCERTAIN. LASTLY, EXPECT
TEMPERATURES TO CONTINUE THEIR WARMING TREND THROUGH WEDNESDAY WITH
HIGHS LARGELY IN THE 70S TO 80S WITH THE WARMEST CONDITIONS EXPECTED
BY WEDNESDAY WEST OF I-29.
AVIATION /06Z TAFS THROUGH 06Z FRIDAY/
ISSUED AT 1013 PM CDT WED JUL 30 2025
LIGHT RAIN CONTINUES TO MOVE SOUTHEAST AND AWAY FROM THE AREA.
IN THE WAKE OF THIS RAINFALL, SCATTERED MVFR FOG OR SMOKE
CONTINUES TO LINGER AND DRIFT SOUTHEAST UNDER A SCATTERED TO
BROKEN MID-LVL DECK.
CLOUDS WILL LINGER THROUGH THE NIGHT WITH A CONTINUATION OF
FOG/SMOKE INTO THURSDAY. IT'S NOT IMPOSSIBLE TO SEE A BRIEF HIGH
MVFR STRATUS DECK TRY TO FILTER SOUTH THROUGH DAYBREAK AS WELL.
THURSDAY WILL FEATURE NORTHEAST WINDS, WITH AFTERNOON CU
DEVELOPING. A NON-ZERO CHANCE FOR A DIURNAL SHOWER IS POSSIBLE,
THOUGH TOO LOW TO INDICATE IN CURRENT TAF. SLIGHT VISIBILITY
REDUCTIONS FROM SMOKE CONTINUE.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
DISCUSSION...05
AVIATION...DUX
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